<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    * {
        margin: 0;
        padding: 0;
    }


    .box1 {
        background-color: blue;
        margin-right: 100px;
    }

    .box2 {
        background-color: brown;
        margin-left: 100px;
    }

    .demo1 {
        background-color: chartreuse;
        margin-bottom: 100px;
    }

    .demo2 {
        background-color: rgb(32, 184, 204);
        margin-top: 100px;
    }
</style>

<body>
    <span class="box1">123</span>
    <span class="box2">456</span>
    <div class="demo1">1</div>
    <div style="overflow: hidden;">
        <div class="demo2">2</div>

    </div>
</body>

</html>